Load Specifications
Load data in caliber 7.21 Firebird with .284 | 154gr | Peregrine VLR-5 bullet and 51 powders. The key underlying parameters are shown in the table above. The recommended powders for this cartridge and bullet combination are ADI AR 2218, Vihtavuori N570 and Hodgdon Retumbo.
Important Notice: DO NOT go below Minimum Charge or above Maximum Charge. Since we have no control over the equipment and components used, any responsibility and liability for the results achieved is rejected.
Only powders/loads that match the current filter criteria are displayed: max pressure of a load ≤ 90% of max. standardized pressure, fill rate ≥ 80% and propellant combustion ≥ 95%. Use the sliders above the tables to adjust these thresholds.
Charge: Powder weight in grains. Start with the minimum load and work up carefully.
FR (Fill Rate): Case fill as a percentage. Values above 100% mean compressed loads.
MaxP / %: Maximum chamber pressure in bar and as a percentage of the standardized maximum for this caliber.
V(0): Muzzle velocity in feet per second (fps) at the standardized barrel length.
z (Powder Burn): Estimated propellant combustion percentage at bullet exit.
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Max Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 86% | 59,364 psi | 89% | 3074 fps | 100% |
| Accurate 8700ᴾ | <<locked>> | 100% | 51,706 psi | 78% | 3058 fps | 97.9% |
| Accurate MAGPRO | <<locked>> | 84% | 58,929 psi | 88% | 3202 fps | 99.9% |
| ADI AR 2209 | <<locked>> | 82% | 56,565 psi | 85% | 3114 fps | 100% |
| ADI AR 2213 | <<locked>> | 86% | 59,538 psi | 89% | 3199 fps | 100% |
| ADI AR 2217 | <<locked>> | 94% | 59,234 psi | 89% | 3179 fps | 100% |
| ADI AR 2218 | <<locked>> | 96% | 55,825 psi | 84% | 3251 fps | 99.3% |
| ADI AR 2225 | <<locked>> | 96% | 59,045 psi | 89% | 3199 fps | 100% |
| Alliant Reloder-19 | <<locked>> | 84% | 60,046 psi | 90% | 3163 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 86% | 59,872 psi | 90% | 3189 fps | 100% |
| Alliant Reloder-23 | <<locked>> | 86% | 58,044 psi | 87% | 3081 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 90% | 59,132 psi | 89% | 3163 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 82% | 59,074 psi | 89% | 3173 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 94% | 57,885 psi | 87% | 3222 fps | 99.2% |
| Alliant Reloder-50 | <<locked>> | 98% | 58,030 psi | 87% | 3215 fps | 99% |
| Baschieri & Pellagri 109 | <<locked>> | 88% | 59,625 psi | 89% | 3156 fps | 99.5% |
| Bofors RP15 | <<locked>> | 88% | 59,234 psi | 89% | 3176 fps | 100% |
| Bofors RP30 | <<locked>> | 92% | 58,900 psi | 88% | 3189 fps | 100% |
| Bofors RP5 | <<locked>> | 86% | 59,872 psi | 90% | 3189 fps | 100% |
| Hodgdon H1000 | <<locked>> | 90% | 56,565 psi | 85% | 3136 fps | 100% |
| Hodgdon H4831 | <<locked>> | 84% | 57,856 psi | 87% | 3123 fps | 100% |
| Hodgdon H4831 SC | <<locked>> | 84% | 56,898 psi | 85% | 3107 fps | 99.9% |
| Hodgdon Retumbo | <<locked>> | 90% | 59,146 psi | 89% | 3268 fps | 100% |
| Hodgdon TrailBossᴾ | <<locked>> | 100% | 37,898 psi | 57% | 2028 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 84% | 57,870 psi | 87% | 3097 fps | 100% |
| IMR 7828 SSC | <<locked>> | 86% | 57,986 psi | 87% | 3179 fps | 100% |
| IMR 7977 Enduron | <<locked>> | 90% | 56,579 psi | 85% | 3048 fps | 96.5% |
| IMR 8133 Enduron | <<locked>> | 98% | 57,566 psi | 86% | 3186 fps | 100% |
| Lovex S071 | <<locked>> | 90% | 57,609 psi | 86% | 3051 fps | 100% |
| Norma 217 | <<locked>> | 98% | 59,088 psi | 89% | 3199 fps | 100% |
| Norma MRP | <<locked>> | 84% | 60,205 psi | 90% | 3199 fps | 100% |
| Ramshot Grand | <<locked>> | 86% | 59,886 psi | 90% | 3205 fps | 100% |
| Ramshot Magnum | <<locked>> | 88% | 58,204 psi | 87% | 3127 fps | 100% |
| ReloadSwiss RS 14ᴾ | <<locked>> | 100% | 38,972 psi | 58% | 2073 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 90% | 60,292 psi | 90% | 3251 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 92% | 59,205 psi | 89% | 3225 fps | 100% |
| Rottweil R 904 | <<locked>> | 82% | 56,782 psi | 85% | 3084 fps | 100% |
| Rottweil R 905 | <<locked>> | 84% | 59,843 psi | 90% | 3156 fps | 100% |
| SNPE Vectan SP 13ᴾ | <<locked>> | 100% | 53,534 psi | 80% | 3071 fps | 97.9% |
| SNPE Vectan Tubal 8000 | <<locked>> | 84% | 59,466 psi | 89% | 3150 fps | 100% |
| Somchem S361 | <<locked>> | 82% | 58,102 psi | 87% | 3071 fps | 100% |
| Somchem S385 | <<locked>> | 84% | 60,031 psi | 90% | 3117 fps | 100% |
| Vihtavuori N165 | <<locked>> | 88% | 60,350 psi | 90% | 3104 fps | 100% |
| Vihtavuori N170 | <<locked>> | 92% | 59,756 psi | 90% | 3146 fps | 98.4% |
| Vihtavuori N555 | <<locked>> | 84% | 59,524 psi | 89% | 3107 fps | 100% |
| Vihtavuori N560 | <<locked>> | 84% | 59,466 psi | 89% | 3212 fps | 100% |
| Vihtavuori N565 | <<locked>> | 88% | 56,884 psi | 85% | 3143 fps | 100% |
| Vihtavuori N568 | <<locked>> | 92% | 59,234 psi | 89% | 3225 fps | 99.9% |
| Vihtavuori N570 | <<locked>> | 92% | 56,724 psi | 85% | 3232 fps | 98.8% |
| Winchester StaBALL HD | <<locked>> | 86% | 59,683 psi | 89% | 3179 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 86% | 60,031 psi | 90% | 3117 fps | 100% |
Recommended = one of the top powders for this cartridge and bullet combination.
Start Load - Barrel Length: 26"
| Powder | Charge | FR | MaxP | % | V(0) | z |
|---|---|---|---|---|---|---|
| Accurate 3100 | <<locked>> | 80% | 48,240 psi | 72% | 2904 fps | 100% |
| Accurate 8700 | <<locked>> | 96% | 44,338 psi | 66% | 2917 fps | 96% |
| Accurate MAGPRO | <<locked>> | 80% | 50,981 psi | 76% | 3068 fps | 99.3% |
| ADI AR 2209 | <<locked>> | 80% | 52,852 psi | 79% | 3054 fps | 100% |
| ADI AR 2213 | <<locked>> | 80% | 48,109 psi | 72% | 3002 fps | 99.5% |
| ADI AR 2217 | <<locked>> | 80% | 35,795 psi | 54% | 2730 fps | 97.2% |
| ADI AR 2218 | 94.4 gr | 88% | 41,205 psi | 62% | 2940 fps | 95.4% |
| ADI AR 2225 | <<locked>> | 80% | 33,040 psi | 50% | 2697 fps | 98.9% |
| Alliant Reloder-19 | <<locked>> | 80% | 52,489 psi | 79% | 3041 fps | 100% |
| Alliant Reloder-22 | <<locked>> | 80% | 48,762 psi | 73% | 3002 fps | 99.9% |
| Alliant Reloder-23 | <<locked>> | 80% | 47,456 psi | 71% | 2917 fps | 100% |
| Alliant Reloder-25 | <<locked>> | 80% | 41,626 psi | 62% | 2871 fps | 100% |
| Alliant Reloder-26 | <<locked>> | 80% | 54,897 psi | 82% | 3110 fps | 100% |
| Alliant Reloder-33 | <<locked>> | 86% | 42,598 psi | 64% | 2930 fps | 95.9% |
| Alliant Reloder-50 | <<locked>> | 90% | 42,685 psi | 64% | 2917 fps | 95.3% |
| Baschieri & Pellagri 109 | <<locked>> | 80% | 45,687 psi | 68% | 2907 fps | 97.1% |
| Bofors RP15 | <<locked>> | 80% | 45,397 psi | 68% | 2936 fps | 99.7% |
| Bofors RP30 | <<locked>> | 80% | 38,682 psi | 58% | 2808 fps | 98.1% |
| Bofors RP5 | <<locked>> | 80% | 48,762 psi | 73% | 3002 fps | 99.9% |
| Hodgdon H1000 | <<locked>> | 80% | 39,015 psi | 58% | 2812 fps | 98.7% |
| Hodgdon H4831 | <<locked>> | 80% | 50,372 psi | 76% | 2995 fps | 99.4% |
| Hodgdon H4831 SC | <<locked>> | 80% | 49,516 psi | 74% | 2979 fps | 99.3% |
| Hodgdon Retumbo | 81 gr | 80% | 40,814 psi | 61% | 2936 fps | 99.7% |
| Hodgdon TrailBoss | <<locked>> | 80% | 28,413 psi | 43% | 1814 fps | 100% |
| IMR 4955 Enduron | <<locked>> | 80% | 50,865 psi | 76% | 2979 fps | 99.6% |
| IMR 7828 SSC | <<locked>> | 80% | 46,934 psi | 70% | 2986 fps | 99.4% |
| IMR 7977 Enduron | <<locked>> | 88% | 52,982 psi | 79% | 2986 fps | 95.7% |
| IMR 8133 Enduron | <<locked>> | 82% | 32,706 psi | 49% | 2667 fps | 95.7% |
| Lovex S071 | <<locked>> | 80% | 41,539 psi | 62% | 2779 fps | 100% |
| Norma 217 | <<locked>> | 80% | 30,879 psi | 46% | 2631 fps | 97.1% |
| Norma MRP | <<locked>> | 80% | 52,199 psi | 78% | 3074 fps | 100% |
| Ramshot Grand | <<locked>> | 80% | 47,616 psi | 71% | 3002 fps | 99.7% |
| Ramshot Magnum | <<locked>> | 80% | 42,873 psi | 64% | 2867 fps | 99.8% |
| ReloadSwiss RS 14 | <<locked>> | 80% | 29,298 psi | 44% | 1860 fps | 100% |
| ReloadSwiss RS 76 | <<locked>> | 80% | 40,509 psi | 61% | 2910 fps | 100% |
| ReloadSwiss RS 80 | <<locked>> | 80% | 37,130 psi | 56% | 2789 fps | 96.1% |
| Rottweil R 904 | <<locked>> | 80% | 53,142 psi | 80% | 3025 fps | 99.9% |
| Rottweil R 905 | <<locked>> | 80% | 52,257 psi | 78% | 3035 fps | 100% |
| SNPE Vectan SP 13 | <<locked>> | 94% | 43,236 psi | 65% | 2871 fps | 95.2% |
| SNPE Vectan Tubal 8000 | <<locked>> | 80% | 51,909 psi | 78% | 3031 fps | 100% |
| Somchem S361 | <<locked>> | 80% | 54,360 psi | 81% | 3012 fps | 99.8% |
| Somchem S385 | <<locked>> | 80% | 52,489 psi | 79% | 3002 fps | 100% |
| Vihtavuori N165 | <<locked>> | 80% | 46,035 psi | 69% | 2874 fps | 99.9% |
| Vihtavuori N170 | <<locked>> | 84% | 45,310 psi | 68% | 2884 fps | 95.2% |
| Vihtavuori N555 | <<locked>> | 80% | 52,228 psi | 78% | 2999 fps | 100% |
| Vihtavuori N560 | <<locked>> | 80% | 51,619 psi | 77% | 3077 fps | 99.6% |
| Vihtavuori N565 | <<locked>> | 80% | 42,975 psi | 64% | 2884 fps | 98.5% |
| Vihtavuori N568 | <<locked>> | 80% | 38,159 psi | 57% | 2808 fps | 95.9% |
| Vihtavuori N570 | 88.2 gr | 84% | 42,148 psi | 63% | 2936 fps | 95.2% |
| Winchester StaBALL HD | <<locked>> | 80% | 47,485 psi | 71% | 2995 fps | 100% |
| Winchester Supreme 780 | <<locked>> | 80% | 48,791 psi | 73% | 2936 fps | 99.9% |
Recommended = one of the top powders for this cartridge and bullet combination.
ᴾ possible press load - work up slowly to this load while watching for signs of excessive pressure.
This overview compares 51 powders for 7.21 Firebird loaded with the .284 | 154gr | Peregrine VLR-5. Hodgdon Retumbo delivers the highest muzzle velocity at 3,268 fps; across all powders the maximum-charge window runs from 2,028 fps to 3,268 fps. Accurate 8700 gives the best case fill at 100 %, and 51 of the 51 powders fall inside the usable 80–100 % fill window.
Relative to the caliber's maximum pressure (460 MPa), the top charges use 57–90 %, leaving at least 10 % headroom. The 154.0 gr projectile in 0.284" calls for a 1:9.0 twist; slower twists will usually not stabilise this weight. Accurate 8700, Hodgdon TrailBoss, ReloadSwiss RS 14 reach 100 % fill or more at maximum charge, so these are compressed loads: they need a long drop tube to seat cleanly and react sensitively to the case capacity of your own brass lot. ADI AR 2218, Vihtavuori N570, Hodgdon Retumbo rank at the top here: for 7.21 Firebird with the .284 | 154gr | Peregrine VLR-5 they combine a high case fill with complete burn and sit in the upper velocity band. Always begin at the start load and work up in small increments while checking case and primer for pressure signs.